import pandas as pd
pd.set_option('display.unicode.east_asian_width',True)
df=pd.DataFrame([['A','C','B'],['B','A',"C"],["A","B","C"],["A","B","C"]],columns=['a','b','c'])
print('原始数据\n',df)
print('按频数降序统计a列\n',df.value_counts('a'))
print('按频率升序统计b列:\n',df.value_counts('b',normalize=True,ascending=True))
print('按频率降序统计所有列\n',df.value_counts())
print('使用describe()统计所有列\n',df.describe())